﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    class SumUtils
    {
        private int a;
        private int b;
        private double c;
        private double d;
        private string e;
        private string f;

        public int Add(int a, int b)
        {
            return a + b;
        }
        public double add(int a, int b)
        {
            return a + b;
        }
        public string add (string a, string b)
        {
            return a + b;
        }
        public int dao(int a)
        {
            int sum = 0;
            for (int i = 1; i < a; i++)
            {
                sum = sum + i;
            }
            return sum;
        }
    }
}
